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Impurities segregated to grain boundaries of a material essentially alter its fracture behavior. A prime example is sulfur segregation-induced embrittlement of nickel, where an observed relation between sulfur-induced amorphization of grain boundaries and embrittlement remains unexplained. Here, 48x10(6)-atom reactive-force-field molecular dynamics(More)
Generation of stacking faults (SFs) during the growth of nanowires (NWs) is a major concern for the efficiency of NW-based devices such as solar cells. Here, molecular-dynamics simulation of a [111]-oriented gallium arsenide NW reveals an atomistic mechanism of SF generation. Spatial distribution of the adatom energy on the (111)B top surface exhibits a(More)
Generation of twin defects during the growth of semiconductor nanowires is a major concern, but their effects on electronic properties are not well understood. Here, combined quantum-mechanical and molecular-dynamics simulations reveal that the radiative decay time of an exciton increases due to twin. Furthermore, the twin-scattering contribution to(More)
While nanowires and nanosheets (NSs) grown on lattice-mismatched substrates have a number of promising technological applications such as solar cells, generation of misfit dislocations (MFDs) at their interfaces is a major concern for the efficiency of these devices. Here, combined molecular-dynamics and quantum-mechanical simulations are used to study MFDs(More)
Nanowires (NWs) exhibit thermo-mechanical properties that are distinct from their bulk properties, and their understanding is critical for the reliability, manufacturability, and optimization of a wide range of devices consisting of NWs. Here, molecular-dynamics simulation reveals a rich size-temperature " phase diagram " for the mechanical response of a(More)
Based on molecular-dynamics simulations validated with quantum-mechanical calculations, we predict that (111) twin planes in a [111]-oriented GaAs nanowire attain attractive interactions mediated by surface strain. This gives rise to a self-replication mechanism that continuously generates a twin superlattice in a nanowire during growth. We demonstrate(More)
Recent experimental and theoretical studies have shown an essential role of sulfur segregation-induced amorphization of crystalline nickel leading to its embrittlement at a critical sulfur concentration of $14%, but the atomistic mechanism of the amorphization remains unexplained. Here, molecular dynamics simulations reveal that the large steric size of(More)
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